Pneumatic motor



(No Model.) 3 Sheets-Sheet l. G. W. SMITH.

` PNEUMATIG MOTOR. No. 591,018.

Patented 00t.'5,1897.

3 Sheets-Sheet 2.

(No Model.)

G. W. SMITH. PNBUMATIG MOTOR.

No. 591,018. Patented Oct. 5,1897..

(No Model.) 3 sheets-sheet 3 G. W. SMITH. PNEUMATIG MOTOR.

No. 591,018.. Patented Oct. 5,1897.

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PNEUMATIO MOTOR.

SPECIFICATION forming part of Letters Patent No. 591,018, dated October5, 189'?.

Application filed February 13, 1897l Serial No. 623,271. (No model.)

b @ZZ whom t 'muy concern,.-

Be it known that I, GEORGE W. SMITH, a citizen of the United States,residing at Topeka, in the county of Shawnee and State of Kansas, haveinvented certain new and useful Improvements in a Combined PortablePneumatic Motor and Drilling and Tapping Machine,of which the followingis a specification.

My invention relates to that class of pneumatic drills and tappingmachines in which the prime mover is a rotary spindle having slidingblades in the piston adapted to be spread apart by the action of theduid-pressure acting within the same; and the Object of the invention isto provide a simple, economical, and efficient pneumatic drilling andtapping machine.

The invention consists in the features, combinations, and details ofconstruction hereinafter described and claimed.

In the accom pan ying drawings, Figure l is a side elevation of acomplete machine or tool constructed in accordance with my improvements;Fig. 2, an end elevation of the same; Fig. 3, an enlarged sectionalelevation taken on line 3 ot' Figs. 2 and 4, looking in the direction ofthe arrow; Fig. 4, a transverse sectional view taken on line 4 of Fig.8; Fig. 5, a Sectional view of the rotating piston; Fig. G, a plan viewof one ot the piston ends; and Figs. 7 and 8, section views taken onlines 7 and 8, respectively, of Fig. 8, looking in the direction ot' thearrows.

In constructing a tool in accordance with my improvements I make acasing A ofthe desired size and shape adapted to hold, contain, andinclose the operative part-s of the mechanism. This casingis madepreferably in one integral portion, so as to provide a substantiallycylindrical duid-pressure chamber d and a mechanism-box a', and isprovided with caps A" A2, one at each end thereof. A partition A3divides the mechanism-box from the the duid-pressure chamber.

Rotatably mounted in the fluid-pressure chamber is a piston B, havingbearing portions b at each end thereof, one in the cap of the casing andthe other in .a suitable boss or hub in the partition. This piston ispreferably made of two semicylindrical portions b h', held together ateach end by means of the piston ends B', which have semicylindricalbosses b2, -and provide a channel b3, in which the piston-blades C areheld and may reciprocate when desired. The piston ends are secured tothe semicylindrical portions of the piston by means of screws b4, thoughany other desired means may be used.

To receive the direct and expansive force of the duid-pressure so as torotate the piston, I provide two piston-blades C C', and each of suchblades with a cylinder o' at the inner end thereof. Theseblade-cylinders are open at their inner ends and have each a movablepiston in the same arranged adjacent to each other, so that ahelically-coiled spring c3 may be inserted between the same and normallyhold such pistons apart and allow the blades to bear with the leastpossible friction against the cylindrical press u re-chamber. vTheblades are provided with passages C2, leading to the blade-cylinders, sothat fluid-pressure may enter the same and, acting against the pistonsin the blade-cylinders, force the same inwardly, and rby such actionkeep the blades in proper contact with theinner surface of theHuid-pressure chamber, so that they may com pensate automatically forthe Wear of such parts.

The fluid-pressure chamber is provided with an inlet-passage o4 and anexhaust-passage d5, (shown particularly in Fig. 4,) so that asliuidpressure enters the chamber it impinges against the blade C' andtends to rotate the piston until the blade reaches the position shown bythe blade C and allows the expanded pressure to escape. A portion of thepressure enters through the passage C2 in the blade-piston and forcesthe piston inwardly, so as to create a reactionary force against theblade and tend to keep it in close contact with the wall of the cylinderand pre'- vent leakage.

To transmit power and motion from the rotary spindle to a shank D, Iprovide a set of com pound gears d, d', d2, and d3, which serve todecrease the speed and increase the power, though of course anyarrangement of gears may be used to accomplish the same result.

I claiml. In a portable pneumatic drilling-tool,the combination of acasing provided with a fluidpressure chamber and inlet and outletpassages, a rotatable piston mounted therein composed of two hollowseinicylindrical portions and two end portions having,` semicircularprojections forming transverse channels on their inner faces adapted toreceive and guide the blade mechanism, two reciprocating' blades movablymounted in the :rotating` piston, and a cylinder and piston on the innerend of each of the blades having commu nication with the fluid-pressurechamber of the casing so that fluid-pressure may operate theblade-pistons, substantially as and for the purpose described.

2. In a portable pneumatic drilling-tooLthe combination of acasing`provided With a fluidpressure chamber and inlet and outlet passages, arotatable piston mounted therein composed of two hollow semicylindricalportions and two end portions having,` semicircu-A lar projectionsforming transverse channels on their inner faces adapted to receive andguide the blade mechanism, two reciprocating blades movably mounted inthe rotating piston and provided with pressure-cylinders on their innerends, a piston in the pressurecylinder of each of the blades having`communication with the fluid -pressure chamber of the casing,` so thatfluid-pressure may operate the blade-pistons, and spring mechanisminserted between the blade-pistons to hold the same apart, substantiallyas described.

GEORGE W. SMITH. Vitnesses:

A. D. GRAY, D. WHITMER.

